Double-plenum or double-chamber manifolds or splitters are used chiefly in air inlet systems in which the EGR gases are recycled. They enable the engine cylinders to be supplied by two flows of gas, one based on fresh air and the other made up of the EGR gases.
These two flows of gas can be kept separate until their injection into the cylinder head. It is therefore necessary to provide two circulation circuits for the manifold that are independent of each other, from the inlet opening to the pipe outlets.
This results in a complex structure, particularly in the case of a flattened formation of the manifold designed to reduce the amount of space occupied.
Currently, this type of manifold is at best formed by assembling at least three separate component parts.